reply to danielc
Re: Cisco DPC3010 Cable Modem They did accept the gateway version of your modem, the DPC3825 in my case. I think you may stand a better chance going that route.
I had a web chat with one of their techs to confirm that they would accept the DPC3825 so that at least I had some sort of proof of a 'conversation' on the subject before I actually bought the gateway. I have it running in bridged mode i.e. acting as a plain modem.
DPC3825 (bridged mode) - WRT610N + Tomato - Panasonic KX-TGP500 - Asterisk 22.214.171.124 with Asterisk GUI on Virtual Server
Anveo - FreePhoneLine - Voxbeam - Numbergroup - Callcentric - VoIP.MS - Localphone - UKDDI